There are three forms of sleep apnea: central (CSA), obstructive (OSA), and complex or mixed sleep apnea (i.e., a combination of central and obstructive) constituting 0.4%, 84% and 15% of cases, respectively. In CSA, breathing is interrupted by a lack of respiratory effort; in OSA, breathing is interrupted by a physical block to airflow despite respiratory effort, and snoring is common. Referring now to OSA, more than 12 million American adults have obstructive sleep apnea. It is a disorder in which breathing is repeatedly, but briefly, interrupted during sleep. Obstructive sleep apnea occurs when the muscles in the back of the throat fail to keep the airway open, making it difficult to breathe. It is more common in people who are overweight, but it can affect anyone. For example, some small children may have obstructive sleep apnea due to enlarged tonsil tissue in their throats. For those with OSA, the airway collapses or becomes blocked during sleep. This causes shallow breathing, or pauses in breathing, which leads to fragmented sleep and low blood oxygen levels. OSA is commonly accompanied by snoring, as well. This is referred to as Upper Airway Restrictive Syndrome (UARS) and may also derive from medical conditions such as deviated septum, large turbinates, narrow palate, long soft palate etc. This condition is considered to be the same as OSA and is diagnosed and treated similarly. Sleep bruxism is another sleep disorder that occurs concurrently with OSA in a majority of patients. This is forceful side to side, front to back or vertical clenching and unclenching of the mandible. This can occur in all age groups and occurs in the general population at a frequency of between 8% and 26%.
Some patients with obstructive or other types of sleep apnea may benefit from surgery. The type of surgery depends on the cause of the sleep apnea. Examples for common types of surgical procedures for sleep apnea include removing the tonsils and adenoids, if these organs are blocking the airway. This can be especially helpful in the case of children. In advanced, non-responsive cases, the mandible may be broken and lengthened, to move the tongue out of the throat region. Another surgery involves placing a small hole and tube in the windpipe, causing airflow through the tube into the lungs. This is carried out in severe cases of sleep apnea. In still other cases, the uvula (the tissue that hangs down in the middle of the back of the throat), and part of the roof of the mouth at the back of the throat may be removed.
Another common treatment for sleep apnea, which does not require invasive surgery, is called continuous positive airway pressure (CPAP). In this treatment, the patient wears a special mask over nose and mouth (or inserts into the nose) while sleeping. The mask keeps the wearer's airway open by increasing the air pressure breathed in by the wearer. However, such masks cover a large portion of the face and head, are generally uncomfortable, and may leak or can fall off, thus reducing effectiveness. They do not treat sleep bruxism.
Still further, devices of the prior art have been designed to aid in obstructive sleep apnea problems. U.S. Pat. No. 5,427,117, issued to Thornton et al., discloses a dental device which includes adjustable upper and lower arch trays. The device has an upper arch and lower arch with an adjustable post that extends from the upper arch and contacts the lower arch, so that the user's lower jaw is extended forward with respect to the upper. The post shown in these references is shaped to engage with the lower arch, so that the user's mouth cannot be opened more than a predetermined amount while the post is engaged.
Still another device has been described in U.S. Pat. No. 5,829,441 issued to Kidd et al., which discloses a mandible extension dental device including adjustable upper and lower arch trays. Each upper and lower arch tray includes a U-shaped tray body attached to the upper and lower teeth. The device is adjusted to selectively cause extension of the user's lower jaw when the mouth is closed. The upper and lower trays dovetail with a depending hook located in the front of the device.
U.S. Pat. No. 6,766,802, issued to Keropian et al., discloses an appliance that covers the inside of the upper teeth only with an open palate similar to an upper orthodontic retainer. This device further has a retainer wire to hold the anterior teeth in place, or to move such teeth backwards, and a raised strip that extends from an incisor tip (biting edge) of central incisors to separate the posterior teeth and hold the tongue down.
Another device, the ALF (Advanced Lightwire Functionals) appliance is a cemented expansion appliance for orthodontic treatment. These devices are cemented with bands around the first molars with a wire custom bent to fit the teeth. Activation of the wire expands a plate. Another device is to a type of removable retainer that actively moves the teeth for final positioning. This appliance completely covers the teeth and does not have a definitive bite.
Thus, while there are many different ways of attempting to alleviate problems associated with OSA, there is still room for improvement. There is a need in the field to find devices which are least obtrusive, more comfortable, easy to use, durable, and most effective.